Bipolar endoscopic instrument

ABSTRACT

A bipolar endoscopic instrument including a tubular stem having a distal end and a proximal end. The stem distal end supports two jaws that are pivotable relative to one another. The proximal end of the tubular stem has a bipolar hf plug inserted therein at an acute angle to a push/pull wire. The plug applies a bipolar output of a high-frequency (hf) voltage source into the inside of the instrument. The inserted end of the hf plug is shaped such that the plug contacts are axially insulated from each other and each plug contact touches an electrically conducting contact element inside the instrument which, in turn, is connected in electrically conducting manner to one of the two jaws. A unit is present inside the instrument and includes the two contact elements and an insulator electrically separating the contact elements. The hf plug engages the insulator while a particular plug contact touches a particular contact element.

[0001] The present invention relates to a bipolar endoscopic instrumentdefined in the preamble of claim 1.

[0002] An instrument of this kind for instance may be bipolar forceps ortongs of which the arms or jaws make contact with the two terminals of ahigh-frequency (hf) source. Illustratively bipolar forceps are used toseize and coagulate tissue. However they also may be bipolar scissorscutting and simultaneously coagulating the cut tissue surfaces.

[0003] In general the power is applied from the two output terminals ofthe hf source, through the proximal instrument end, to the jaws. Asregards the above cited bipolar endoscopic instruments, the two outputterminals are insulated from each other and, by means of a two-contacthf plug, are connected to the inside of the instrument. The end of thehf plug inserted into the instrument is configured in a way that the twoplug contacts shall be axially shifted from each other, each makingcontact inside the instrument with a contact element electricallyconnected to a particular jaw. In general the hf plug is configured atan acute angle to the thrust and/or pull element or wire, hereafterpush/pull wire, and to the proximal instrument end.

[0004] The application of output power from the two terminals of the hfsource through the two-contact hf plug to the inside of the instrumentraises problems. Because of the relative compactness inside theinstrument, considerable effort must be devoted to conduct the powerfrom the two hf source terminals through a two-contact hf plug into theinstrument inside and to guide this power within the instrument to thedistal jaws.

[0005] Accordingly it is the objective of the present invention tosimplify the transition from the hf plug into the inside of a bipolarendoscopic instrument of the above kind.

[0006] This problem is solved by an instrument exhibiting the featuresof claim 1.

[0007] Inside the instrument of the invention, there is a unitcomprising two contact elements configured in axially consecutive mannerand electrically insulated from each other by an electric insulator.

[0008] The angle and the site of insertion of the hf plug are selectedin such a way that the plug, by its applied end, engages said insulator,this plug end being configured in such a way that each time one hfsource terminal shall make contact with one contact element of saidunit.

[0009] By using the above unit, the two hf source terminals may beconnected in very simple manner through a two-contact hf plug into theinside of the bipolar endoscopic instrument and from there with thecontact elements.

[0010] An advantageous embodiment of said unit is defined in claim 2.Therein the two contact elements are cylindrical and are configuredlongitudinally consecutively on a push/pull element or wire. Theinsulator is disk-shaped and is configured axially between the twocontact elements. Electric connection between the contact elements canbe effectively prevented by axially mounting the insulator between them.

[0011] Another way to electrically separate the unit's two contactelements by means of an insulator is defined by the configuration of theunit in claim 3. Therein the contact elements are tubular and can beconfigured axially into one another. Again a bush-like insulator isinserted between the two contact elements in order to preclude electricconduction between them.

[0012] The manufacture of the contact elements and of the insulator,furthermore the installation of said unit in the instrument, are simpleand easily carried out and therefore also economical.

[0013] Advantageously, in the manner defined in claim 4, one contactelement of the unit is designed to make contact with the push/pull wirewhich in turn also is connected in electrically conducting manner withone jaw. The unit's second contact element is designed in such a waythat it contacts the instrument's stem which in turn is electricallyconnected to the other jaw. In this manner electrical conduction can beestablished between the contact elements and the jaws without resort toadditional components.

[0014] As already mentioned above, the hf plug is inserted at an acuteangle to the push/pull wire in order to improve instrument handling. Inorder to simplify as much as possible the engagement of the hf plug inthe insulator and simultaneously the contact between plug contacts andcontact elements, the unit defined in claim 5 is fitted at the level ofthe insulator with a borehole pointing in the direction of theinstallation angle of the hf plug.

[0015] Said borehole preferably shall be threaded to receive the hf plugwhich in turn is threaded at its installed end. However the boreholealso may be a socket for said plug.

[0016] In order to attain electrical connection between plug contactsand contact elements when the hf plug is inserted into the threadedborehole or the socket, claim 6 advantageously provides that the twoprojecting plug contacts shall exhibit symmetry of rotation. As a resultthe insertion of the hf plug into the instrument does not require aprecise plug-in position because electrical connection shall be attainedat any plug-in position.

[0017] Said unit may be in the form of a prefabricated component made upof individual elements. Illustratively the insulator may be soldered tothe two contact elements. However the individual constituents also maybe separate and be separately inserted into the instrument.

[0018] The invention is elucidated below in relation to two illustrativeembodiments shown in FIGS. 1 and 2.

[0019]FIG. 1 is a vertical cross-section of the proximal end of abipolar endoscopic instrument fitted with a unit defined in claim 2, andFIG. 2 is a vertical cross-section of the proximal end of a bipolarendoscopic instrument fitted with a unit defined in claim 3.

[0020]FIG. 1 shows the proximal end of a bipolar endoscopic instrument 1comprising a stem 11, jaws 18, 19 being mounted at the distal end ofsaid stem, said jaws 18, 19 being electrically connected to the outputterminals A, B of an hf source 14.

[0021] A handle 20 is present at the proximal end of the instrument 1and comprises two scissor grips 2 and 4 that pivot relative to eachother about a common pivot 3.

[0022] The instrument 1 also comprises an axially displaceable pushand/or pull wire 5 of which the proximal end is linked to the grip 4 andof which the distal end engages said jaws 18, 19. When the grip 4 ispivoted, the push-pull wire 5 is adjusted axially in the instrument 1and as a result the jaws pivot relative to each other.

[0023] To this extent the instrument is one of the state of the art.

[0024] As regards the invention, the instrument 1 receives a unit 6enclosing the push/pull wire 5 and comprising an insulator 7 and twocontact elements 8 and 9. A borehole 21 is fitted into the unit 6 andreceives the distal end of an hf plug 10. For the sake of clarity, thehf plug is shown in cross-sectional, schematic manner and then only inthe region of its distal end.

[0025] Two electrically conducting plug contacts 12 and 13 are on thedistal end of the hf plug 10 which in this embodiment exhibits symmetryof rotation, said plug contacts 12 and 13 being connected throughomitted, mutually insulated conductors with the hf-source's outputterminals A, B.

[0026] The plug 10 is inserted in such a way into the borehole 21 of theunit 6 that the plug contacts 12, 13 are electrically kept apart by theinsulator 7 and in that each plug contact 12, 13 makes contact with onecontact element 8 and 9 resp., the latter in turn being electricallyconnected with the push/pull wire 5 resp. the stem 11 fitted with anexternal insulation 16.

[0027] The current from the hf source's terminal A runs from therethrough the plug contact 12 to the contact element 8 and then to thestem 11 and through the stem 11 as far as one of the distal jaws. Thecurrent from the terminal B runs through the plug contact 13 to thecontact element 9 and from there to the push/pull wire 5 which iselectrically connected to the other distal jaw.

[0028] Like FIG. 1, FIG. 2 shows the proximal end of a bipolarendoscopic instrument. However a unit 6′ is fitted according to claim 3with a sleeve-shaped contact element 8′ which is longitudinallydisplaceable by the push/pull wire 5 and furthermore receives aninserted cylindrical contact element 9′. An insulator 7′ is insertedbetween the contact elements 8′ and 9′ and again assumes a cylindricalshape.

[0029] In this embodiment the current goes from the output terminal Bthrough the plug contact 12 to the contact element 9′ and from therethrough the push/pull wire 5 which again is electrically connected toone of the distal jaws. The current from the output terminal A runsthrough the plug contact 13 connected to the contact element 8′ throughthe stem 11 to the other distal jaw.

1. A bipolar endoscopic instrument comprising a tubular stem at thedistal end of which are configured two jaws supported to be mutuallypivotable and at the proximal end of which may be inserted a bipolar hfplug at an acute angle to the push and/or pull wire, hereafter push/pullwire, said plug applying the bipolar output of a high-frequency (hf)voltage source into the inside of said instrument, the hf plug'sgeometry at its inserted end being such that the plug contacts areaxially insulated from each other and in that each plug contact touchesan electrically -conducting contact element inside the instrument whichin turn is connected in electrically conducting manner to an jaw,characterized in that a unit (6, 6′) is present inside the instrument(1) and comprises the two contact elements (8, 9, 8′, 9′) configured inaxial sequence or one into the other and an insulator (7, 7′)electrically separating the contact elements (8, 9, 8′, 9′), said unit(6, 6′) and the hf plug (10) being designed in such manner and beingmounted in the instrument (1) in such a way that the hf plug (10) by itsproximal end enters the insulator (10) and in that a particular plugcontact (12, 13) of the hf plug (10) touches a particular contactelement (8, 9, 8′, 9′).
 2. Bipolar endoscopic instrument as claimed inclaim 1, characterized in that the contact elements (8, 9) of the unit(6) are cylindrical and can be configured consecutively in thelongitudinal direction on the push/pull wire (5), the insulator (7)being in the form of a disk and mounted axially between the contactelements.
 3. Bipolar endoscopic instrument as claimed in claim 1,characterized in that the contact elements (8′, 9′) of the unit (6′) aresocket-shaped and may be mutually inserted longitudinally one in theother on the push/pull wire (5), the insulator (7′) also being in theform of a bush and being mounted radially between said contact elements.4. Bipolar endoscopic instrument as claimed in claim 1, characterized inthat the geometry of the unit (6, 6′) is such that one of the contactelements (8, 9, 8′, 9′) shall make contact by means of the push/pullwire (5) with one of the jaws and the other contact element shall makecontact by means of the tubular stem (11) with the other jaw.
 5. Bipolarendoscopic element as claimed in claims 1 and 2, characterized in thatthe unit (6, 6′) exhibits a borehole (21) at the level of the insulator(7, 7′) and at the same angle as that subtended between the hf plug (10)and the instrument, the hf plug (10) being received by its distal end insaid borehole (21).
 6. Bipolar endoscopic instrument as claimed inclaims 1 and 2, characterized in that the plug contacts issuing from theproximal end of the hf plug (10) exhibit symmetry of rotation. 7.Bipolar endoscopic instrument as claimed in one of the above claims,characterized in that the unit (6, 6′) is a component.